At the heart of the hatchery system is the incubator. It is the incubator that provides the environment for giving life to the fertilized egg and safeguards the survival of the emergent fry. The first incubators that were developed were of a deep matrix type attempting to simulate natural conditions. A standard incubator consisted of birds eye and pea gravel and successive layers of crushed rocks and eggs. This standard incubator satisfied many of the physiological and behavioral requirements of the embryo and eleutheroembryo (embryo after hatching).
However, there remain some difficulties with this type of incubator. Firstly, space requirements for operation and maintenance of this type of incubator are not practical for salmon production. Huge amounts of space are necessary for the gravel and crushed rock. Additionally, the handling and cleaning of the tons of rock and gravel annually in a production hatchery result in tremendous costs. The costs diminish the economic advantages of improved eyed-egg to fry survival rates in the deep matrix incubator.
With the increase in demand by commercial, sport and subsistence fishermen for additional salmon, an industry-wide need for practical and efficient incubators developed. The deep matrix incubator left this demand unsatisfied because of its space and maintenance requirements.
It was left to the Applicant to develop a practical and efficient incubator which increased the survival rate of the fry as well as the hatch rate and the quality of the adult fish at an economically feasible cost.